Heat exchange air circulating unit



Feb. 2, 1932.-

J. H. HOLTON HEAT EXCHANGE AIR CIRCULATING UNIT Filed Sept. 20, 1930 2 Sheets-Sheet INVENTOR. (/0241 4 Hal/017 fifi ATTOR Feb. 2, 1932.

J. H. HOLTON HEAT EXCHANGE AIR CIRCULATING UNIT Filed Sept. 20 1950 2 Sheets-Sheet 2 Patented Feb. 2, 1932 UNITED STATES PATENT OFFICE JOHN H. BOLTON, OF NORRISTOWN, PENNSYLVANIA, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO CARRIER RESEARCH CORPORATION, OF NEWARK, NEW JERSEY, A. COR- PORATION OF NEW JERSEY HEAT EXCHANGE AIR cmcunurme UNIT Application filed September 20, 1930. Serial No. 483,211.

The present invention relates to heat exchange units for the purpose of heating and cooling air for use in rooms.

Some of the objects of the present inven- 1 tion are to provide an improved apparatus for regulating the temperature of a body of air passing through and discharged from such apparatus; to provide a heating unit of standard size and full heating capacity having an air control means for varying the heatingcapacity without loss of air capacity; to provide a controlled heating unit operating with a minimum cost per unit of capacity; to provide an air mixing control which ensures the smooth entrance of tempered air to the discharge fans with an appreciable reduction in turbulence and resistance, thereby efiecting a saving of power and a decrease of noise; to provide a means for maintaining a constant rate of circulation in the room being heated or cooled; to provide a heating unit supplying low temperature air with rapid circulation thereof whereby economy of heating and uniformity of distribution are obtained; to provide a damper control for heaters wherein the controlled openings for passage of air are so proportioned that the full rated quantity of air flow is substantially constant at all damper positions; to provide a heat exchange unit wherein two air inlets communicate with the room in which the unit is located and have a heat exchange element between the inlets so that the air from one inlet passes through the exchange element and the air from the other'inlet mixes with the heated air between the exchange element and the main discharge of the unit; and to provide other improvements as will hereinafter appear.

In the accompanying drawings Fig. 1 represents a front elevation, partly broken away; of a heating and circulating unit embodying one form of the present invention; Fig. 2 represents an end elevation of the same; and Fig. 3 represents on a reduced scale a schematic elevation showing the direction of the air currents as drawn into the fan vortex.

- Referring to the drawings one form of the wsent invention is shown as embodiedin a casing 10, preferably of metal, and of generally rectangular configuration. The body of the casing 10 terminates an appreciable distance above the floor line and is supported by legs 11 which in this instance are continuations of the respective corner angle bars of the casing 10. This skeleton supporting means allows free unrestricted passage for air from all sides at the floor level and allows the air to enter the casing 10 by way of the open bottom inlet 12. This inlet 12 directs the air vertically upward to pass successively through a heating chamber 13, a temper- ,ing chamber 14, and an exhaust chamber 15,

this latter housing the fans 16 which discharge the air-by way of ducts 17 from the casing 10. As here shown the fans 16 are driven by a common shaft 18 directly connected to a motor 20 which is conveniently mounted on a bracket platform 21 at one end of the casing 10.

For heating the incoming air from the inlet 12, the chamber 13 contains a heating means preferably in the form of a return bend predetermined degree before it enters the chamber 14.

Control of the air leaving the chamber 13 is had in this instance, by locating a deflecting partition 25 at one side of the top of the chamber 13, this partition having one edge fastened to the front plate of the casing while its other edge is secured to a bar 26 which extends horizontally lengthwise of the casing 10 and has its ends connected to the end plates of the casing. The bar 26 is preferably above the level of theline or junction between the partition 25 and the casing front plate so that in assembled condition the partition 25 is inclined to direct the rising air to a throat slot 27 which extends lengthwise of the casing Y 10 and forms the means of communication between the chambers 13 and 14/ An elongated damper 28 of a width sufficient to close the throat slot 27 is pivotally mounted to regulate the amount of air passing through the slot 27, though the arrangement is preferably such that the damper 28 cannot be completely closed at any time.

For introducing relatively cool room air into the chamber 14, an elongated supplemental inlet 30 is formed in the front plate of the casing 10 and extends lengthwise thereof just above the junction line of the partition with the front plate. Thus the partition 25 also directs the supplemental air supply upward and inwardly of the casing 10 to the chamber 14 which it enters under control of a damper 31 arranged in closed position to bridge the space between the bar 26 and the front plate of the casing. Preferably the supplemental air inlet is concealed by the provision of a screen or grille 32 which gives an ornamental finish without decreasing the desired supply of recirculated air. It should be noted that the arrangement of the fans 16, enclosing scrolls and other associated parts is such as to draw the air upwardlyand in an uni-directional path into the scroll of the fan for direct-discharge into the ducts 17. This is important because itavoids cross currents of air and mixing of air moving in different directions which, under ordinary constructions, cause turbulence and with attendant loss in efiiciency.

For automatically controlling the two dampers 28 and 31 so that the proper proportion of the air entering the supplemental inlet 30 to the heated air entering the throat slot 27 can be maintained the two dampers 28 and 31 are interconnected by a link 33 in such a manner that movement of the damper 31 to open position will cause the damper 28 to move to cut down the supply of heated air. Thus the link 33 connects at one end to a rock member 34 fast to the pivot rod 35 of the damper 28, while its other end is connected to another rock member 36 fast to the pivot rod 37 of the damper 31. Motion is transmitted to the rock member 36 by a link 38 pivotally connected to a lever arm 40 which is fulcrumed at 41 and is operated either by hand or by the projecting plunger 42 of a pressure operated diaphragm motor 43. A spring 44 connected between the lever arm 40 and a fixed part 45 serves to return the arm 40 to the position shown in Fig. 1 when the damper 28 is full open and the damper 31 is closed. A pipe 46 leads to the pressure motor 43 from a suitable air supply under control of a thermostat located in the room in which the temperature is to be controlled. Any well known means may be employed for effecting dam er control, however, and the invention is no limited to the specific means here shown. In connection With the dampers 28 and 31 and the inlets which they respectively control it should be noted that the proportions of the inlets which extend the full length of the easing, provide a substantially constant resistance to air flow in all damper positions. .Such a constant resistance means constant air volume (at any given fan speed) which in turn mea ns constant room circulation.

It should also be noted by locating the partition 25 on the inner side of the front plate of the casing and above the heating coil 22 that a standard width casing can be used with all parts contained therein properly proportioned to give full heating capacity of a standard size unit. The advantage of this will be seen when it is realized that if the supplemental air inlet and its damper were beside the coil, the latter would have to be reduced in width so that a reduction of heating capacity would result accompanied by throttling of air and without a proportionate reduction in cost. Increasing the width of the standard unit to correct such a situation does not answer because the result is higher cost per unit of capacity.

In the foregoing one form of apparatus has been described for carrying out the present invention and now in explaining the operation of the apparatus the new result accomplished by the invention will more clearly appear. One feature which is at once apparent to those skilled in the art as difiierentiating from prior structures of this character is that the casing 10 is located for operation in the room which is to be heated and has two inlets for air communicating with the room and no connections extending outside of that room other than the piping by which the heating medium is conveyed to the heating structure 22. Thus two air inlets serve to introduce air to the casing 10 for recirculation in the room as distinguished from air inlets for respectively introducing recirculated air and fresh air. conveys the recirculated air for passage through the heatingstructure 22 while the other air inlet conveys recirculated air to the tempering chamber without contacting with the heating structure 22. Hence the temperature of the air in the room is directly controlled by recirculated air admitted between the heating structure and the main air discharge duct or ducts. The economy and increase in efficiency due to the introduction of recirculated air into the heated air as the latter leaves the heater will be readily apparent when compared with the discharge of recirculated heated air only.

For example with the damper 31 closed and the damper 28 open the heated air may leave the unit and enter the room at say 130 F. with the result the buoyant hot air rises quickly to the top of the room where it has a temperature say of approximately 85 F. while the working zone which is the space to be maintained at a comfortable temperature is Only F. In other words a relatively One air inlet stance (Which is seldom required) the bypass damper is open to reduce the capacity of the unlt in order to control the temperature in the room and as a result the temperature of the discharged air is maintained rela ti vely low while full volume of air and full.

ra of circulation 'of air are maintained. Low temperature air and rapid circulation give the desired economy of heating and uniformity of distribution.

As compared to prior heating units it will readily be apparent that the present invention not only produces a result not heretofore attained but has many advantages not present in other heaters. For example these prior structures stress a high final temperature as a means of satisfactorily maintaining a comfortable temperature in a room and then depend upon the introduction of cold fresh air to modify the final temperature should the latter produce an uncomfortably hot condition. The present invention to the contrary works with a relatively low final temperature which is caused to circulate more or less rapidly to maintain a substantially' uniform and comfortable temperature in the room. No cold outside air is required and the room is heated economically and with losses reduced to a minimum. Further more the air is drawn through the heat exchange element instead of being blown or pushed through and hence counter currents and eddies which produce turbulence and variable air temperatures are avoided. In connection with this elimination in turbulence attention "is directed to Fig. 3 wherein the travel of the air is depicted from the two air inlets to the fan. Thus the arrangement is such that the dampers 28 and 31 in addition to controlling the inlets serve also as deflectors to lead the air columns toward the rear of the unit where it all enters the inlet vortex in its direction of rotation. This construction avoids the losses in efliciency of prior units wherein a portion of theincoming air always opposes the swirling inlet vortex. It is this turbulence in prior structures which increases the required horsepower for a given volume of air as well as giving noisy operation.

Having thus described my invention, I claim:

1. A heat exchange air circulating unit the room to said exchange element and the other of said air inlets supplying controlled volumes of air from the room to mix with the heated air after the latter leaves said exchange element, and means for discharging the mixed air in constant volume to said room.

2. A heat exchange air circulating unit "comprising a heat exchange element, a casing enclosing said element and having two air inlets communicating with the room in which said casing is located, one of said air inlets supplying recirculated air in varying volume to said exchange element and the other of said air inlets supplying recirculated air continuously and in varying volume to mix with the heated air after the latter leaves said exchange element, means for discharging the mixed air in constant volume to said room, and dampers respectively controlling the proportions of the volumes of air passing through said inlets.

3. A heat exchange air circulating unit comprising a heat exchange element, a casing enclosing said element and having two.

air inlets communicating with the room in which said casing is located, one of said air .inlets supplying recirculated air to said exarranged to deflect the air entering from lpoth inlets toward theinlet vortex of the 4. A heat exchange air circulating unit comprising a casing having an air inlet at one end thereof and an air inlet intermediate the ends thereof, both of said inlets communicating with the room in which said casing is located, a partition between said inlets forming a heating chamber and a diluting chamber with a passage between said chambers, a heat exchange element in said heating chamber, means to discharge air from said casing,'and means to vary the size of said passage while also varying the size of the air inlet above said partition.

5. A heat exchange air circulating unit comprising a casing having an air inlet at one end thereof and an air inlet intermediate the ends thereof, both of said inlets communicatingwith the roomin which said casing is located, a partition between said inlets forming a heating chamber 'a'nd a diluting chambenwith a passage between said chambers, a heat exchange element in said heating chamber, means to discharge air from said casing, and means for proportionately in- 5 creasing the size of said passage while decreasing the size of the air inlet above said partition.

6. A heat exchange air circulating unit comprising a vertically disposed casing having an air inlet at the bottom and a second air inlet extending lengthwise of the front of said casing, a partition inclined inwardly and upwardly from the front of said casing below said second inlet to form a passage extending lengthwise of the rear wall of said casing, a heat exchange element below said partition and in the path of air entering said first inlet, and a pair of interconnected dampers for respectively controlling said second air inlet and said passage.

7. A heat exchange air circulating unit comprising a heat exchange element, 2. casing enclosing said element and having a discharge outlet and two air inlets communicating with the room in which said casing is located, one of said air inlets supplying recir culated air in controlled volume to said exchange element and the other of said air inlets supplying a controlled volume of recirculated air above a predetermined minimum to mix with the heated air after the latter leaves said exchange element, and means including a fan located between said heat exchange element and said discharge outlet for drawing and directing air to said outlet.

through said device, said first and second means being connected so that a predetermined minimum of air will be continuously drawn within the unit through said second inlet.

Signed at Philadelphia,'county of Philw delphia, State of Pennsylvania, this 18th day of September, 1930.

JOHN H. HOLTON.

8. A heat exchange air circulating unit I comprising a heat exchange element, a casing enclosing said element having a discharge outlet and a pluralityof air inlets, 40 a fan located. adjacent said outlet, means to rotate said fan, and dampers to direct air from said inlets respectively in varying Volume, but in a mixture of constant volume to enter said fan in the direction of fan rotation.

9. A heat exchange air circulating unit comprising a heat exchange element, a casing enclosing said element having a discharge outlet and a plurality of air inlets, a fan located adjacent said outlet, means to rotate said 54 fan, and air directing devices to vary respectively the volumes of air from both of said inlets and to cause a mixture of said air in constant volume to approach the vortex of the fan in the direction of fanrotation.

10. An air circulating unit of the character described comprising a heat exchange device, a fan, a plurality of inlets for admitting air within the unit from the room in which the unit is located responsive to the operation of the fan, first means for controlling a volume of air admitted through one of said inlets and routed through said device, second means for controlling a volume of air drawn within the unit through a second of 5 said inlets for diluting the air passing 

